陕西几种主要土壤脲酶热力学特征初探

Study on soil urease thermodynamic characteristics of major soils in Shaanxi

计算陕西省 7种土壤 19个不同肥力土样的脲酶热力学参数结果显示 ,土壤脲酶的ΔG≠ >0、Δ H≠>0、ΔS≠ <0 ,反映出酶促反应不能自发进行 ,必须由外界供给能量 ,才能克服位阻上的障碍 ;除水稻土外 ,其余土样脲酶的Δ G≠ 值低肥力土样大于高肥力 ,Δ H≠ 和ΔS≠ 值变化不明显 ,相关分析等揭示出土样脲酶ΔG≠ 与土壤肥力中的有机质呈显著相关 。

The urease thermodynamic parameters were analyzed in nineteen samples of seven soil types in Shaanxi. The results showed as follows:The soil urease ΔG ≠>0,ΔH ≠>0, ΔS ≠< 0 showed that it was not possible for soil urease reaction until energy imposed;the higher fertile samples urease ΔG ≠ were higher than the lower samples except paddy soil;urease ΔH ≠,ΔS ≠ values did not observably vary among soils tested; ΔG ≠ was remarkable correlation with soil fertility by correlation analyses and the average of all thermodynamic parameters varied by the same law.